Communication load balancing using distributed antenna beam steering techniques

ABSTRACT

A load balancing method for cellular communication systems and communication systems in general is described where beam steering antenna systems on the client or user side of the communication link are used to optimize load balancing among the base stations or nodes. A system controller containing an algorithm is implemented to control the radiation modes from the client or user devices to assign the client or user devices to the various base stations or nodes and to dynamically vary the network load across the cellular or communication system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of commonly owned U.S. Ser.No. 14/109,837, filed Dec. 17, 2013, titled “BEAM STEERING TECHNIQUESAPPLIED TO CELLULAR SYSTEMS”; which claims benefit of U.S. ProvisionalApplication Ser. No. 61738325, filed Dec. 17, 2012; and

this application further claims benefit of priority with U.S.Provisional Application Ser. No. 62/112,090, filed Feb. 4, 2015;

the contents of each of which are hereby incorporated by reference.

FIELD OF INVENTION

This invention relates generally to the field of wireless communication;and more particularly, to dynamic load balancing of a communicationnetwork using beam steering antenna systems at the client or user sideof the communication link.

BACKGROUND

Data centric mobile devices and applications are putting capacityconstraints on cellular and wireless local area network (WLAN)communication systems as more users move to these higher data ratedevices. The growth of video file sharing is increasing the data raterequirements for both uplink and downlink in the cellular and WLANenvironment. As a result, new optimization techniques are required toload balance the communication network to maintain system capacity andreduce the need of adding additional base terminals.

Current and future cellular communication systems will require higherperformance from the antenna systems on the mobile or user end toimprove system capacity and optimize load balance across the baseterminals or nodes. As new generations of handsets, gateways, and otherwireless communication devices become embedded with more applicationsand the need for bandwidth becomes greater, new antenna systems will berequired to optimize link quality over larger bandwidths. Specifically,better control of the radiated field from the antenna system on themobile side of the communication link will be required to provide bettercommunication link quality for an antenna system tasked to covermultiple frequency bands. Control and optimization of radiatedperformance of subscriber devices in the cellular system can beimplemented to load balance the existing networks.

As more subscribers migrate to higher data rate applications anddevices, there will be a greater need to dynamically adjust uplink anddownlink radiated performance per subscriber per cell in a network.Antenna beam steering techniques are well known and utilized on the baseterminal side of the cellular communication link, but are currentlymissing from the mobile side primarily due to size constraints of thedevices in use. For example, current cell phones, smart phones, andtablet devices are not large enough nor have the internal volumeavailable to support multi-element antenna arrays needed to effectuatetraditional beam steering techniques.

SUMMARY

A load balancing method for cellular communication systems andcommunication systems in general is described wherein beam steeringantenna systems on the client or user side of the communication link areused to optimize load balancing among the base stations or nodes (i.e.the “network”). A system controller including an algorithm isimplemented to control the radiation modes from the client or userdevices (for example, cell phones, smart phones, tablet devices, and onthe like) to assign the client or user devices to the various basestations or nodes and to dynamically vary the network load across thecellular or communication system network.

BRIEF DESCRIPTION OF THE DRAWINGS

The claimed invention can be further understood upon a thorough reviewof the following detailed description in conjunction with the appendeddrawings, wherein:

FIG. 1A shows a signal strength profile of a cellular network inaccordance with an illustrated embodiment;

FIG. 1B shows another signal strength profile of a cellular network inaccordance with an illustrated embodiment;

FIG. 2A shows a base terminal tower with an antenna array in accordancewith an illustrated embodiment;

FIG. 2B shows multiple smaller regions of a cell of a cellular networkin accordance with an illustrated embodiment;

FIG. 3A shows a base terminal antenna system having a fixed radiationpattern in accordance with an illustrated embodiment;

FIG. 3B shows regions in a multi-cell network in accordance with anillustrated embodiment;

FIG. 4A shows a plot of a cellular network with antenna systemperformance on a wireless terminal set at a 0 dB baseline in accordancewith an illustrated embodiment;

FIG. 4B shows a plot of a cellular network with antenna systemperformance on a wireless terminal set at a 3 dB improvement level inaccordance with an illustrated embodiment;

FIG. 4C shows a plot of a cellular network with antenna systemperformance on a wireless terminal set at a 5 dB improvement level inaccordance with an illustrated embodiment;

FIG. 5 shows a system on a wireless terminal that uses a modal antennato optimize load balancing in accordance with an illustrated embodiment;

FIG. 6A shows a three-cell network with seven wireless terminals inaccordance with an illustrated embodiment;

FIG. 6B shows a plot of cell loading for the three cells of FIG. 6A inaccordance with an illustrated embodiment;

FIG. 6C shows a plot of SINR measured for each wireless terminal foreach base terminal of FIG. 6A in accordance with an illustratedembodiment;

FIG. 7A shows another three-cell network with seven wireless terminalsin accordance with an illustrated embodiment;

FIG. 7B shows a wireless terminal having modal antenna systemspossessing two radiation modes in accordance with an illustratedembodiment;

FIG. 7C shows a plot of SINR measured for each radiation mode of themodal antennas for each base terminal of FIG. 7A in accordance with anillustrated embodiment;

FIG. 8 shows another cellular network with wireless terminals in thenetwork having modal antenna system in accordance with an illustratedembodiment;

FIG. 9 shows another cellular network with wireless terminals in thenetwork having modal antenna system in accordance with an illustratedembodiment;

FIG. 10 shows an exemplary flowchart for an algorithm or methodology toload balance a communication network in accordance with an illustratedembodiment;

FIG. 11 shows another exemplary flowchart for an algorithm ormethodology to load balance a communication network in accordance withan illustrated embodiment;

FIG. 12 shows another exemplary flowchart for an algorithm ormethodology to load balance a communication network in accordance withan illustrated embodiment;

DETAILED DESCRIPTION

In the instant disclosure, for purposes of explanation and notlimitation, details and descriptions are set forth in order to provide athorough understanding of the claimed invention. However, it will beapparent to those skilled in the art that the claimed invention may bepracticed in other embodiments that depart from these details anddescriptions without departing from the spirit and scope of theinvention. Certain embodiments will be described below with reference tothe drawings wherein illustrative features are denoted by referencenumerals.

In the following description and in the figures, like elements areidentified with like reference numerals. The use of “e.g.,” “etc,” and“or” indicates non-exclusive alternatives without limitation, unlessotherwise noted. The use of “including” or “includes” means “including,but not limited to,” or “includes, but not limited to,” unless otherwisenoted.

As used herein, the term “and/or” placed between a first entity and asecond entity means one of (1) the first entity, (2) the second entity,and (3) the first entity and the second entity. Multiple entities listedwith “and/or” should be construed in the same manner, i.e., “one ormore” of the entities so conjoined. Other entities may optionally bepresent other than the entities specifically identified by the “and/or”clause, whether related or unrelated to those entities specificallyidentified. Thus, as a non-limiting example, a reference to “A and/orB”, when used in conjunction with open-ended language such as“comprising” can refer, in one embodiment, to A only (optionallyincluding entities other than B); in another embodiment, to B only(optionally including entities other than A); in yet another embodiment,to both A and B (optionally including other entities). These entitiesmay refer to elements, actions, structures, steps, operations, values,and the like.

Now, a load balancing method for cellular communication systems andcommunication systems in general is described, wherein beam steeringantenna systems on the client or user side of the communication link areused to optimize load balancing among the base stations or nodes (i.e.the “network”). A system controller including an algorithm isimplemented to control the radiation modes from the client or userdevices (for example, cell phones, smart phones, tablet devices, and onthe like) to assign the client or user devices to the various basestations or nodes and to dynamically vary the network load across thecellular or communication system network.Client-side beam steeringantennas are described in commonly owned U.S. Ser. No 14/965,881, filedDec. 10, 2015, titled “ANTENNA AND METHOD FOR STEERING ANTENNA BEAMDIRECTION FOR WIFI APPLICATIONS”; U.S. Ser. No. 14/144,461, filed Dec.30, 2013, and titled “ANTENNA AND METHOD FOR STEERING ANTENNA BEAMDIRECTION”; U.S. Ser. No. 13/726,477, filed Dec. 24, 2012, titled“ANTENNA AND METHOD FOR STEERING ANTENNA BEAM DIRECTION”, now U.S. Pat.No. 8,648,755, issued Feb. 2, 2011; U.S. Ser. No. 13/029,564, filed Feb.17, 2011, titled “ANTENNA AND METHOD FOR STEERING ANTENNA BEAMDIRECTION”, now U.S. Pat. No. 8,362,962, issued Jan. 29, 2013; and U.S.Ser. No. 12/043,090, filed Mar. 5, 2008, titled “ANTENNA AND METHOD FORSTEERING ANTENNA BEAM DIRECTION”, now U.S. Pat. No. 7,911,402, issuedMar. 22, 2011; the contents of each of which is hereby incorporated byreference.

Each of these references describes a client-side beam steering antennatechnique (beam steering using the antenna system of the device) whereina single antenna is capable of generating multiple radiating modes. Thisis effectuated with the use of offset parasitic elements that alter thecurrent distribution on the driven antenna as the reactive load on theparasitic is varied. This beam steering technique, wherein multiplemodes are generated, is referred to as a “modal antenna” technique, andan antenna configured to alter radiating modes in this fashion will bereferred to herein as a “modal antenna”. This antenna architecturesolves the problem associated with a lack of volume in mobile devices toaccommodate antenna arrays needed to implement more traditional beamsteering hardware.

The above-described modal antenna technique can be implemented in mobileand fixed communication devices across a network and used to address andoptimize the load distribution of users and data across the network.Modal antennas that are integrated into the mobile devices on a networkprovide the capability to direct antenna gain of the mobile device toone or more preferred base terminals or nodes within range of the mobiledevice. Compared to a conventional passive antenna used with a mobiledevice, the modal antenna can provide improved antenna gain performancein the direction of multiple base terminals or nodes, with thiscapability being used to load balance a network when a subset of, or allof, the mobile and fixed devices on a network possess this capability.

The following embodiments describe systems and methods for loadbalancing in a communication system. Hardware and algorithm componentsalong with a system controller are described which enable this novelload balancing technique. A beam steering technique may be implementedwith a wide variety of current load balancing techniques that may besoftware implementations. For example, a common approach used incommunication network load balancing is to define a balance index whichis used to measure the balance of resources in a system. The balanceindex was first introduced by D. Chiu and R. Jain “Analysis of theIncrease and Decrease Algorithms for Congestion Avoidance in ComputerNetworks”, Computer Networks and ISDN Systems, Vol. 17, no. 1, pp 1-14,1989. It is defined as

${\xi_{1} = \frac{( {\sum_{i}\rho_{i}} )^{2}}{K{\sum_{i}\rho_{i}^{2}}}},$where K is the number of neighboring base terminals over which the loadcan be distributed, and ρi are load vectors associated with each baseterminal.

The load vectors vary between 0 and 1, and if all base terminals havethe same load level, then ξ₁=1. As additional wireless terminals enter acellular network or as wireless terminals move in relation to the baseterminals, the load vectors can be surveyed and the wireless terminalcan be assigned to a base terminal to attempt to maintain a balancedloading of the network. The embodiments described herein may be used tomore optimally connect a wireless terminal to a base terminal during theload balancing process and to provide better communication linkperformance between the wireless terminal and multiple base terminals,which will result in more wireless terminal/base terminal pairings oroptions as a load balancing process is implemented. The balance index ofthe network may be calculated for several beam steering configurationsspread across a large number of wireless terminals, and the beamsteering states may be selected to optimize for network load.

As used herein “base terminal” includes a network side base stationtower or other network terminal.

The term “wireless terminal” includes wireless devices, repeaters,access points, and other client-side terminals and subscriber devicesthat are configured to connect with base terminals via a communicationlink.

Another common approach implemented in load balancing schemes is termedthe max Signal to Interference and Noise Ratio (max-SINR) approach,where SINR is surveyed across the population of wireless terminals on anetwork, and wireless terminals are distributed across base terminals tomaximize SINR performance. This approach will ensure good connectivityfor the wireless terminals but does not take into account data rate forthe wireless terminals, because a good SINR may be achieved for awireless terminal as it is assigned to a base terminal, but the selectedbase terminal might already be serving a large number of wirelessterminals that will impact the network resources that can be assigned tothe new wireless terminal. In this scenario, the beam steering techniquedescribed herein will provide better performance across the populationof wireless terminals due to the ability to direct the antenna radiationpattern gain maxima in a direction of a less loaded base terminal ornode where equivalent SINR can be achieved compared to a more heavilyloaded base terminal.

The ability to beam steer the antenna system associated with a wirelessterminal in a cellular or node based network will result in severalbenefits compared to a passive antenna associated with the wirelessterminal: improved signal strength of the communication link betweenwireless terminal and base terminal, a potential increase in baseterminals that can be accessed by a wireless terminal during the loadbalancing process, and the ability to provide a more equal link qualitybetween base terminal and wireless terminal at some instances due tobeam steering functionality

Embodiments herein describe a load balancing scheme based upon beamsteering attributes assigned to mobile and fixed communication devices(subscribers) on a cellular or other node based network where the beamsteering function of the antenna system at the subscribers are commandedand controlled from a system controller on the network. An algorithm isimplemented in a system controller to control antenna system beam statefunctionality to load balance cells or nodes associated with thecommunication network. Optimizing antenna system gain performance in thedirection of intended communication as well as reducing antenna systemgain performance in the direction of interferers are also considered andoptimized during the load balancing process. A subset of subscriberdevices, or all subscriber devices, may incorporate antenna beamsteering systems within the network, with maximum benefit occurring whenall subscriber devices provide beam steering capability. The uplink anddownlink channels of the network are used to provide subscriber antennasystem status to the network and for the network to send beam steeringcommands to the subscribers. This load balancing technique may beimplemented on both networks that have beam steering antenna systems atthe base terminals or nodes, and on networks that have fixed antennasystems at the base terminals or nodes.

In some embodiments, in a multi-cell wireless communication network, oneor more subscriber communication devices have beam steering antennasystems capable of generating multiple radiation modes. A systemcontroller comprised of a processor and algorithm is part of the networkand provides the control and monitoring function for the subscribers.Subscriber loading per cell may be monitored by the system controlleralong with the number of subscribers associated with each cell. Thealgorithm implements a decision process to assign subscribers tospecific cells based upon cell loading. Specifically, the subscriberdevices that contain beam steering antenna systems are queried, andcommunication link performance with cells in the vicinity of thesubscriber device for radiation modes of the antenna system aredetermined using a metric such as Signal to Interference and Noise Ratio(SINR), Channel Quality Indicator (CQI), Receive Signal StrengthIndicator (RSSI), Bit Error Rate (BER), or any other metric that wouldbe similarly implemented by those having skill in the art. A matrixconsisting of subscriber device performance per radiation mode for cellsmay be developed and used to assign subscribers to cells to spread oroptimize the loading across the network. Antenna beam state forsubscribers may become a key metric to track, prior to handover of thesubscriber between cells. This technique may be implemented to provideload balance optimization for the cells in a network for both uplink anddownlink operation.

In some embodiments, all subscriber communication devices on amulti-cell wireless communication network have beam steering antennasystems capable of generating multiple radiation modes. This results inan optimized network where all subscriber devices may be monitored forantenna beam steering performance with multiple cells to assess bestnetwork load balancing.

In some embodiments, a multi-cell wireless communication network,wherein one or more subscriber communication devices each with beamsteering antenna systems capable of generating multiple radiation modes,the network may possess a fault correction mode where radiation modesfor subscriber devices may be selected to off-load a cell that has afailure or partial failure mechanism. A system controller comprised of aprocessor and algorithm is part of the network and provides the controland monitoring function for the subscribers. When a fault is detected,for example, with hardware associated with a cell in the network thatcan affect communication link performance between the cell andsubscribers, the controller with algorithm may implement a failurecorrection mode where subscribers are off-loaded to adjacent or othercells. The antenna beam steering systems associated with subscribers aresurveyed by the controller and antenna beam steering mode and cellpairings may be implemented to avoid use of the cell containing thefault.

In some embodiments, the algorithm residing in the system controller maybe configured to implement a decision process such that a subset ofsubscribers receive preference over other subscribers as the loadbalancing process is applied to the network. The preference of thesubset of subscribers results in improved communication performance, forexample, higher data rate, with this preference applied by selectingradiation modes for the subscribers on the network that providesimproved connections to cells within the network. This processimplemented by the algorithm assigns priority to load balancing thenetwork and improving communication link performance of a subset ofsubscribers at the expense of the rest of the subscribers on thenetwork. For example, a radiation mode selection for a subscriber may beselected to improve the connection with a selected base terminal ornode, with the communication link improvement achieved from theradiation mode selection resulting in increased SINR such that a higherorder of modulation may be achieved, resulting in a higher data rate. Asubscriber in the same cell and connected to the same base terminal ornode that is not part of the subset of subscribers slated for improvedperformance may be commanded by the controller, based on the algorithm,to select a radiation mode that provides optimal communication linkperformance, allowing for a specific data rate applied to thesubscriber. Network resources may be freed up for preferred subscribersby optimizing radiation mode performance for all subscribers.

In some embodiments, the algorithm included in the system controller maybe configured to monitor the movement of subscribers and implement adecision process that will anticipate the handover between cells andensure maximum link quality for a subscriber along his or hertrajectory. For example, a radiation mode selection for a subscriber maybe selected to improve the connection with a next base terminal or nodethat the subscriber will go through in conjunction with the loadbalancing process.

In some embodiments, the algorithm included in the system controller maybe configured to implement a decision process such that communicationlink performance is equalized across the entire population ofsubscribers on the network as the load balancing process is applied tothe network. The process results in an attempt to equalize communicationlink performance across the population of subscribers, with a resultbeing that network resources are unevenly distributed across thesubscribers. For example, as the network is configured to load balancethe cells within the network by radiation mode selection of theindividual subscriber devices, more network resources will need to bedirected to subscribers in regions of cells where communication linkperformance is degraded compared to other regions of cells. Additionalblockage of communication signals due to walls, buildings, or otherobstructions and/or increased range between the base terminal or nodeand the subscriber may result in a weaker signal compared to otherportions of a cell that are closer to the base terminal or node or wherethere are fewer blockages from obstructions.

In some embodiments, the algorithm included in the system controller mayuse one or more metrics, such as, but not limited to, predicted SINR,RSSI, or BER average over a certain period time for all subscribers inorder to implement a decision process such that communication linkperformance may be equalized over a certain period across the entirepopulation of subscribers on the network as the load balancing processis applied to the network.

In some embodiments, a multi-cell wireless communication networkincludes one or more subscriber communication devices having beamsteering antenna systems capable of generating multiple radiation modesand the base terminals also having antennas coupled to them that arecapable of generating multiple radiation modes. The radiation modes forthe antennas coupled to the base terminals may be the result of standardantenna array techniques where multiple antenna elements are spaced aset distance apart and fed in unison using a feed structure to allow forconnection of the array to a single transceiver port. A systemcontroller comprised of a processor and algorithm is part of the networkand provides the control and monitoring function for the subscribers.Subscriber loading per cell may be monitored by the system controlleralong with the number of subscribers associated with each cell. Thealgorithm may implement a decision process to assign subscribers tospecific cells based upon cell loading. Specifically, the subscriberdevices that contain beam steering antenna systems may be queried, andcommunication link performance with cells in the vicinity of thesubscriber device for radiation modes of the antenna system may bedetermined, using a metric such as SINR, CQI, RSSI, BER, or othersuitable metric. A matrix consisting of subscriber device performanceper radiation mode for cells may be developed and used to assignsubscribers to cells to spread or optimize the loading across thenetwork. Antenna beam state for subscribers becomes a key metric totrack, prior to handover of a subscriber between cells. This techniquemay be implemented to provide load balance optimization for the cells ina network for both uplink and downlink operation.

Now turning to the drawings, FIGS. 1A and 1B illustrate a signalstrength profile of a cellular network 10. FIG. 1A shows an exemplarysignal strength profile of the cells, operated by base terminals 1 to 7,where macroscopic fading in SINR difference is considered, with caxisbeing limited to 10 dB. This provides a clearer representation of theradiated signals in the individual cells. For example, region 17 hashigh SINR for the base terminal or node 5. A soft hand-off (or handover)region 15 is denoted in FIG. 1A and represents an area where a wirelessterminal can connect to two or more base terminals, for example, baseterminals 5 and 6. A scale is provided denoting SINR, and a “softhand-off region” is defined as regions where signal strength from two ormore base terminals are within a set range, for example range A′ between0 and 4. A more accurate representation of the network is shown in FIG.1B where macroscopic and shadow fading are considered. This type ofsignal strength variation in cells is more realistic and representativeof actual system characteristics. The soft hand-off (or handover) region15 denoted in FIG. 1B by an outlined shape represents a broad area wherea wireless terminal can connect to two or more base terminals, forexample, base terminals 5 and 6. A high SINR region 17 is shown withrespect to base terminal 5. Base terminals are denoted 1 through 7 as inFIG. 1A, above.

FIG. 2A illustrates a base terminal tower 20 with an antenna array 21.The antenna array may implement a standard antenna array technique knownin the art to scan the radiation pattern 22 in various directions in thecell (i.e. base station terminal can implement a form of antenna beamsteering). The antenna array 21 may be used to break up a cell intomultiple smaller regions, for example, regions 24, 26, and 28 of cell Ashown in FIG. 2B, illustrating an idealized cell coverage from an array.

FIGS. 3(A-B) illustrate, in accordance with some embodiments, atechnique where the base terminal antenna system 20 has a fixedradiation pattern 22, but the antenna systems 30 (not shown) associatedwith the wireless terminals 32 (e.g., mobile phones, smart phones,tablets, and on the like) have a beam steering capability. Thiscapability may be realized using a modal antenna, which is capable ofgenerating multiple radiation patterns from a single antenna structure.For example, FIG. 3A shows the wireless terminal 32 with a firstradiation mode 33 a, and the wireless terminal 32 (same device)configured with a second radiation mode 33 b Of the antenna system.While the antenna systems of individual devices can be configured in oneof a plurality of modes, the illustrated embodiment contemplates atwo-mode modal antenna for simplification.

FIG. 3B shows the regions in a multi-cell network that may be optimallycovered by the two radiation modes of the antenna system 30 (not shown)on the wireless terminal 32. For example, in region 34, the tworadiation modes of the of antenna system 30 of the wireless terminal 32provide equivalent performance. Base station terminals 20 are shown withbolded dots at the junction of cells. For region 35, the first radiationmode provides a specified and better level of performance in this regioncompared to the second radiation mode. On the other hand, for region 36,the second radiation mode provides a specified and better level ofperformance in this region.

In some embodiments, one or more devices on a network can be implementedwith a modal antenna having multiple radiation modes, the modal antennasof these devices may be used to provide improved antenna efficiency toincrease signal strength in a cellular system. For example, FIGS. 4(A-C)illustrate three plots of a same cellular network where antenna systemperformance on a wireless terminal is respectively set at a 0 dBbaseline (FIG. 4A), 3 dB improvement (FIG. 4B), and 5 dB improvementlevel (FIG. 4C). The figures show regions within the cells of thenetwork that can support various modulation schemes, with the modulationschemes dependent on the signal strength that can be supported orprovided at specific locations within the cell. As the antenna systemperformance on the wireless terminal improves from a 0 dB relative valueto 5 dB improvement, the regions within the cells that can supporthigher orders of modulation (and higher data rates) increases.

FIG. 5 illustrates, in accordance with some embodiments, an antennasystem 30 on a wireless terminal 32 that uses a modal antenna 50 tooptimize load balancing of the network by selecting the best radiationmode from a plurality of possible radiation modes of the modal antennato a specific cell. In this illustrated embodiment, the wirelessterminal 32 is shown in the soft hand-off region 15 (between baseterminals 5, 6, and 7). The region 17 has high SINR for base terminal 5.The wireless terminal 32 includes a modal antenna 50, an antenna tuningmodule (ATM) 51, and an algorithm 53 resident in baseband 52. Controlsignals are sent from the ATM from baseband. In this exemplaryembodiment, the algorithm monitors CQI, RSSI, or other metric from baseterminals 5, 6, and 7, and selects a radiation mode of the modal antennato connect with one terminal and minimize connection to the other twoterminals. For example, the selected mode of the modal antenna mayproduce a gain in the direction of an intended base terminal, and mayfurther produce a null in the direction of one or two base terminalsthat are not desired for the communication link between the device andthe network.

FIGS. 6(A-C) illustrate, in some embodiments, a three-cell (A, B, C)network 60 with seven wireless terminals 61 a; 61 b; 61 c; 61 d; 61 e;61 f; and 61 g (i.e., handsets 1 to 7), with these wireless terminals(handsets) possessing passive antennas (fixed radiation pattern). Forthis illustrated embodiment, a plot of cell loading for the three cellsis shown in FIG. 6B, along with a plot of SINR measured for eachwireless terminal for each base terminal (cell) shown in FIG. 6C. InFIG. 6B, it is shown that cell A has the highest loading (three of theseven handsets), whereas cells B and C each are loaded with twohandsets, respectively. Here, the base station tower can implement beamsteering, but as described above, the individual devices include passive(fixed) radiation modes.

FIGS. 7(A-C), in accordance with some embodiments, illustrate athree-cell network 70 with seven wireless terminals 61 a; 61 b; 61 c; 61d; 61 e; 61 f; and 61 g (i.e. handsets 1 to 7), with each of thesewireless terminals having modal antenna systems possessing two radiationmodes as shown in FIG. 7B, including a first radiation mode 33 a and asecond radiation mode 33 b. For this illustrated embodiment, a plot ofSINR measured for each radiation mode of the modal antennas for eachbase terminal (cell) is shown in FIG. 7C. The network is configured tosend control signals through baseband or other similar means in order tocommand individual devices to vary the mode of the respective modalantenna. For each mode, SINR is sampled, and data is communicated to thenetwork. The network determines globally which devices should beconfigured with each of the respective base station towers, and whichdevices are linked in each of the corresponding cells of the networkusing an algorithm as described herein. Once determined, the networkcommunicates to each device control signals for configuration of therespective modal antenna system. In this regard, load balancing isaccomplished through the network sampling device modes and controllingthe modes of each device to balance network resources.

FIG. 8 illustrates, in some embodiments, a cellular network 80 withwireless terminals in the network having modal antenna systems, where asystem controller 82, including an algorithm, is used to providecommands for the network during a load balancing process. The modalantenna system in each of the wireless terminals may be altered tooptimize network loading. FIG. 8 shows control lines between the systemcontroller 82 and the base terminals 84, and wireless links 83 betweenthe system controller and the wireless terminals 32. Although thediagram shows the wireless links coming from the system controller, itshould be understood by those with skill in the art that the wirelessterminals can connect to the system controller through the baseterminals 20. FIG. 9 illustrates, in some embodiments, a cellularnetwork 90 with wireless terminals 32 in the network each having modalantenna system, where a system controller 92, including an algorithm, isused to provide commands for the network during a load balancingprocess. While in this illustrated embodiment each of the wirelessterminals includes a modal antenna, it is possible that some of thewireless terminals may be limited to passive antenna systems. In thisillustrated embodiment, both the modal antenna systems in the respectivewireless terminals 32 and the base terminals have beam steering antennasystems. The radiation mode in the base terminals may be altered tooptimize network loading, and in addition the mode of the wirelessterminals may further be altered for optimizing load balancing. FIG. 9shows control lines 93; 94 between the system controller 92 and the baseterminals 20 and the wireless terminals 32. The control lines to thewireless terminals may be wireless connections.

FIG. 10, in accordance with some embodiments, illustrates an algorithmor methodology 100, included in, for example, a system controller, toload balance a communication network when the wireless terminals in thenetwork include modal antenna systems which allow for a beam steeringcapability. The base terminals in this illustrated embodiment havepassive antenna system. Equal communication link performance is a goalfor this process while the network is being balanced. In step 102, thealgorithm surveys the load per cell (or node). In step 104, thealgorithm populates a matrix of communication link quality per radiationmode of the wireless terminals for the base terminals (or nodes) thatare within range of the wireless terminals. In step 106, the algorithmselects radiation modes of the wireless terminals to balance cellloading with equal performance across the wireless terminals. Thealgorithm then repeats the process at step 102.

In some embodiments, all wireless terminals in the network includeantenna systems such that a plurality of radiation modes can begenerated for uplink and/or downlink communication, with each radiationmode possessing a different radiation pattern and/or polarizationcharacteristics.

As noted herein, metrics such as SINR, CQI, RSSI, or BER and/orthroughput may be used to assign communication link performance. In someembodiments, averages of the metrics (SINR, CQI, RSSI, or BER and/orthroughput) may be predicted over a certain period of time before andused to assign communication link performance.

Downlink communication system performance, defined as transmission fromone or more base terminals (or nodes) to one or more wireless terminals,may be optimized for network loading across the cells or nodes.Similarly, uplink communication system performance, defined astransmission from one or more wireless terminals to one or more baseterminals (or nodes), may be optimized for network loading across thecells or nodes. In some embodiments, both uplink and downlinkcommunication system performance may be optimized for network loadingacross the cells or nodes.

In some embodiments, the algorithm included in the system controller maybe configured to implement a decision process such that a subset ofwireless terminals receives preference over other wireless terminals asthe load balancing process is applied to the network. The preference ofthe subset of wireless terminals results in improved communicationperformance, such as higher data rate, with this preference applied byselecting radiation modes for the wireless terminals in the network thatprovide improved connections to cells within the network.

FIG. 11, in accordance with some embodiments, illustrates an algorithmor methodology 110 to load balance a communication network when thewireless terminals in the network include modal antenna systems whichallow for a beam steering capability. The algorithm allows for adetermination as to whether to provide equal communication linkperformance to the wireless terminals or to optimize communication linkperformance across a subset of the wireless terminals as the network isbeing balanced. The base terminals in this illustrated embodiment havepassive antenna systems. In step 112, the algorithm surveys the load percell (or node). In step 114, the algorithm populates a matrix ofcommunication link quality per radiation mode of the wireless terminalsfor the base terminals (or nodes) that are within range of the wirelessterminals. In step 116, the algorithm determines whether equalcommunication link performance is desired across the wireless terminals.If desired, the algorithm proceeds to step 118 to select radiation modesof the wireless terminals to balance cell loading with equal performanceacross the wireless terminals. The algorithm then proceeds to step 122and repeats the process at step 112. Back to step 116, if equalcommunication link performance is not desired across the wirelessterminals, the algorithm proceeds to step 120 to select radiation modesof the wireless terminals to balance cell loading while optimizingperformance for a subset of the wireless terminals. The algorithm thenproceeds to step 122 and repeats the process at step 112. In someembodiments, the communication link performance may thus be equalizedacross the entire population of wireless terminals in the network as theload balancing process is applied to the network. The process may resultin at least an attempt to equalize communication link performance acrossthe population of wireless terminals, with a result being that networkresources may be unevenly distributed across the wireless terminals.

FIG. 12, in accordance with some embodiments, illustrates an algorithmor methodology to load balance a communication network when the wirelessterminals on the network contain modal antenna systems which allow for abeam steering capability and the base terminals have beam steeringantenna system. The algorithm allows for a determination as to whetherto provide equal communication link performance to the wirelessterminals or to optimize communication link performance across a subsetof the wireless terminals as the network is balanced. In step 132, thealgorithm surveys the load per cell (or node). In step 134, thealgorithm populates a matrix of communication link quality per radiationmode of the wireless terminals and beam state of the base terminals forthe base terminals (or nodes) that are within range of the wirelessterminals. In step 136, the algorithm determines whether equalcommunication link performance is desired across the wireless terminals.If desired, the algorithm proceeds to step 138 to select radiation modesof the wireless terminals and the base terminals to balance cell loadingwith equal performance across the wireless terminals. The algorithm thenproceeds to step 142 and repeats the process at step 132. Back to step136, if equal communication link performance is not desired across thewireless terminals, the algorithm proceeds to step 140 to selectradiation modes of the wireless terminals and base terminals to balancecell loading while optimizing performance for a subset of the wirelessterminals. The algorithm then proceeds to step 142 and repeats theprocess at step 132.

Similar to the descriptions above for FIG. 10, for the algorithm ormethodology of FIG. 12, in some embodiments, all wireless terminals inthe network include antenna systems such that a plurality of radiationmodes can be generated for uplink and/or downlink communication, witheach radiation mode possessing a different radiation pattern and/orpolarization characteristics. Metrics such as SINR, CQI, RSSI, or BERand/or throughput may be used to assign communication link performance.In some embodiments, averages of the metrics (SINR, CQI, RSSI, or BERand/or throughput) may be predicted over a certain period of time beforeand used to assign communication link performance. Downlinkcommunication system performance, defined as transmission from one ormore base terminals (or nodes) to one or more wireless terminals, may beoptimized for network loading across the cells or nodes. Similarly,uplink communication system performance, defined as transmission fromone or more wireless terminals to one or more base terminals (or nodes),may be optimized for network loading across the cells or nodes. In someembodiments, both uplink and downlink communication system performancemay be optimized for network loading across the cells or nodes. In someembodiments, the algorithm residing in the system controller may beconfigured to implement a decision process such that a subset ofwireless terminals receives preference over other wireless terminals asthe load balancing process is applied to the network. The preference ofthe subset of wireless terminals results in improved communicationperformance, such as higher data rate, with this preference applied byselecting radiation modes for the wireless terminals in the network thatprovides improved connections to cells within the network. In still someother embodiments, the algorithm may be configured to implement adecision process such that communication link performance is equalizedacross the entire population of wireless terminals on the network as theload balancing process is being applied to the network. The processresults in an attempt to equalize communication link performance acrossthe population of wireless terminals, with a typical result being thatnetwork resources are unevenly distributed across the wirelessterminals.

As noted herein, in some embodiments, in a network where one or morewireless terminals with beam steering antenna systems capable ofgenerating multiple radiation modes is implemented, the networkpossesses a fault correction mode where radiation modes for wirelessterminals are selected to off-load a cell or node that has a failure orpartial failure mechanism. A system controller, comprised of a processorand an algorithm, may be part of the network and provides the controland monitoring function for the wireless terminals. When a fault isdetected with hardware associated with a cell in the network that canaffect communication link performance between the cell and the wirelessterminals, the controller with the algorithm may implement a failurecorrection mode where subscribers are off-loaded to adjacent or othercells. The antenna beam steering systems associated with the subscribersare surveyed by the controller, and antenna beam steering mode and cellpairings are implemented to avoid use of the cell containing the fault.

What is claimed is:
 1. A method of load balancing in a communicationsnetwork comprising a wireless client device including a modal antennacomprising a parasitic element, the modal antenna configurable in aplurality of radiation modes for uplink and downlink communication, witheach of the plurality of radiation modes possessing a differentradiation pattern or polarization characteristic; a plurality of baseterminals, each base terminal associated with a cell in a plurality ofcells in the network and configured to provide uplink and downlinkcommunication capability to the wireless client device when the wirelessclient device is within the cell; and a system controller coupled to thecommunication network, the system controller including an algorithm forselecting a radiation mode of the plurality of radiation modes for thewireless client device; the method comprising: surveying communicationlink performance of the wireless client device in each of the pluralityof radiation modes of the modal antenna with each of the plurality ofthe base terminals of the communications network that are within a rangeof the wireless client device; and selecting the radiation mode for themodal antenna of the wireless client device for uplink and downlinkcommunication based at least in part on balancing of a load across thecommunications network and based at least in part on the communicationlink performance between the wireless client device in each of theplurality of radiation modes and each of the plurality of base terminalsthat are within range of the wireless client device.
 2. The method ofload balancing in a communications network of claim 1, wherein SINR(Signal to Interference and Noise Ratio), CQI (Channel QualityIndicator), RSSI (Receive Signal Strength Indicator), BER (Bit ErrorRate), or throughput is used to further assign communication linkperformance.
 3. The method of load balancing in a communications networkof claim 1, wherein SINR (Signal to Interference and Noise Ratio), CQI(Channel Quality Indicator), RSSI (Receive Signal Strength Indicator),BER (Bit Error Rate), or throughput averages are predicted over acertain period of time before and used to further assign communicationlink performance.
 4. The method of load balancing in a communicationsnetwork of claim 1, wherein downlink communication system performance isincreased for network loading across the cells.
 5. The method of loadbalancing in a communications network of claim 1, wherein uplinkcommunication system performance is increased for network loading acrossthe cells.
 6. The method of load balancing in a communications networkof claim 1, wherein both uplink and downlink communication systemperformance is increased for network loading across the cells.
 7. Themethod of load balancing in a communications network of claim 1, whereinthe algorithm included in the system controller is further configured toimplement a decision process across a plurality of wireless clientdevices connected to the network such that a subset of the plurality ofthe wireless client devices receive preference over other wirelessclient devices of the plurality of wireless client devices.
 8. Themethod of load balancing in a communications network of claim 1, whereinthe algorithm included in the system controller is further configured toimplement a decision process across a plurality of wireless clientdevices connected to the network such that communication linkperformance is equalized across an entire population of the plurality ofwireless client devices.
 9. The method of load balancing in acommunications network of claim 1, wherein the radiation mode for thewireless client device is selected to off-load a cell of the pluralityof cells that has a failure or partial failure mechanism in a faultcorrection mode.
 10. The method of load balancing in a communicationsnetwork of claim 1, wherein the modal antenna of the wireless clientdevice comprises a modal single antenna.
 11. The method of loadbalancing in a communications network of claim 10, wherein selectingradiation modes from the modal antenna of the wireless client devicecomprises selecting radiation modes of a respective single modal antennaof the wireless client device for uplink and downlink communication toincrease balance of the load across the communications network.